DESCRIPTION

The artefact consists of five rods of elliptical section, built with brick masonry arches. Rods, 254m long, are connected on top by a cemented mixed material hood, filling the areas between the arches. The surface was originally protected by a timber coating, having the function to protect the walls against the abrasive action of the material transported by Sesia river. The foundation of the artefact consisted of a cemented material grade slab, stiffened by three longitudinal spurs.
The lowering of Sesia’s riverbed, has first caused the removal of the previously deposited alluvial material, and subsequently the undermining of the upstream pier and a jump in correspondence to the downstream one.
Therefore, during high water, the walls were solicited by very considerable efforts.
For the reinforcement of the structure were first put in place metal bars to seam the arches of the lateral rods.
Soon after ground recompression injections were performed, upstream and downstream the artefact.
In a second phase of the work it has been restored the statics of the grade slab, by means of the execution of cement injections for filling of the cavities and the implementation of micropiles in correspondence of the abutment of the arches.
The surface protection wooden boards, were finally replaced by a jet in R/C.
Downstream the artefact was located a stilling basin to slow down Sesia’s current speed, and to reduce the erosive action on the Siphon.